1. Field of the Invention
The present invention relates to a regulator for an underwater breathing apparatus of the type comprising a body, a duct in the said body for delivery of breathable mixture, a shutter seat in the said duct, a shutter of soft material stressed by an adjustable spring towards the said shutter seat, and a push button acting via a lever on the shutter to control it to move away from the shutter seat upon manual delivery of breathable mixture.
2. Description of the Prior Art
In regulators of the type considered it has been found that during long periods of inactivity of the regulator, for example during the winter season, the soft shutter is incised by its shutter seat because of the large force with which it is compressed by the adjustable spring.
The incision of the shutter, whilst not per se prejudicial to the seal of the shutter itself, causes an extension of the adjustable spring which loses part of the original load. In this way, upon reestablishment of normal operating conditions, the spring is no longer as able to combat the pressure of the breathable mixture giving rise to losses.
It has been suggested that the shutter be spaced from its seat during the said periods of inactivity by a complete compression of the adjustable spring.
Over a long period however such compression causes weakening of the spring necessitating its replacement.